As we know, the roll call of live pitches reads like an international who’s who: Coca-Cola, Johnson & Johnson, L’Oréal, Procter & Gamble, Volkswagen etc.

Neither WPP’s 70-year-old founder, Sir Martin Sorrell, nor his Group M leader, Irwin Gotlieb (who has been in the media business for more than 40 years), can remember anything quite like it. Sorrell attributed the wave of reviews to client insecurities, not least around the current measurement systems.

As traditional TV viewing switches to mobile screens and newspaper readers to mobile browsers, accountancy problems that underpin trading have emerged. But it is online where the real trust issues have emerged.

'The thing that leaders were less keen to talk about is procurement and the commoditisation of the business'

Citing a Nielsen study that found 40 per cent of digital ads are not reaching their target audience, as well as Google statistics that suggest it’s nearer to 50 per cent, Weed captured the mood: "I’m pretty simplistic. We need to get standards to talk about 100 per cent viewability. We need to get what we pay for – and if we don’t, this wonderful industry around digital advertising is going to start undermining itself."

Weed admitted he was not surprised by the "industry chaos" right now, due to just how quickly the business is changing, but stressed it needs to be addressed.

The stakes couldn’t be higher. The UK is set to become the first country in which more than half of adspend is directed towards digital. A key driver has been the shift to programmatic trading. An Internet Advertising Bureau report this week suggests digital now accounts for half of all display ads, or almost £1 billion. Similar trends are being tracked globally.

ZenithOptimedia’s global chief executive, Steve King, was among those to acknowledge that the new opportunities presented by the move to programmatic, and the rise of "machine-based learning at scale", will be a factor in any major media review.

The thing that leaders were less keen to talk about is the continued power of procurement and the commoditisation of the media business. Whether any of these sprawling multimarket reviews can escape being cost-cutting exercises remains to be seen.